Advancements in communication, and other, technologies have permitted the introduction, and popular usage, of new types of communication systems. The advancements, e.g., permit increases in the rates at which data is communicated and provide manners by which to communicate data over non ideal communication channels.
New types of radio communication systems are, e.g., exemplary of communication systems that have incorporated advancements in communication technologies. Communication channels of a radio communication system are formed upon radio links rather than upon wireline connections. Because radio links are utilized upon which to form the communication channels, the need for conventional wireline connections to be established between sending and receiving stations of a communication system are obviated. Free of the need to form wireline connections between the sending and receiving stations, a radio communication system is permitting of communications between locations at which formation of wireline connections would not be possible. And, a radio communication system is amenable for implementation as a mobile communication system in which one, or more, of the communication stations is provided with mobility to form a mobile communication system.
Many communication systems utilize digital communication techniques that permit more efficient communication of data than that generally permitted through the use of analog communication techniques. Because of the particular need in a radio communication system to efficiently utilize the spectrum allocated for the formation of radio communication channels upon which to communicate data, the use of digital communication techniques is particularly advantageously implemented therein.
When digital communication techniques are utilized, information that is to be communicated is digitized. In one common technique, the digitized information is formatted in to packets according to a selected packet formatting scheme, and the packets are communicated to effectuate the communication. Individual ones, or groups, of the packets are communicated, for instance, at discrete intervals. And, once communicated, the data packets are concatenated together to recreate an informational content of the data contained therein.
Because data packets need not be communicated continuously but rather can be communicated at discrete intervals, a dedicated communication channel need not be allocated for a single communication session between a single set of communication stations. Instead, a single channel can be shared amongst a plurality of different sending and receiving station-pairs. Because a single channel can be utilized to effectuate communications by the plurality of pairs of communication stations, improved communication capacity is possible.
Communications utilizing packet-formatted data are effectuated, for instance, in conventional LANs (Local Area Networks). Wireless networks, operable in manners analogous to wired LAN's have also been developed. And, these wireless networks, referred to as WLANs (Wireless Local Area Networks), are utilized to communicate packets of data over a radio-link, thereby to effectuate communications between a sending and a receiving station.
An IEEE (Institute of Electrical and Electronic Engineers) 802.11 series of Standards sets forth operating protocols for various packet-based communication schemes. 802.11-based wireless local area networks have been implemented, and mobile terminals operable to communicate with network-based WLAN devices are increasingly utilized to effectuate communication services.
The wireless local area networks are typically operated by operators and include network structure that encompasses selected geographical areas. That is, network infrastructures of wireless local area networks provide communication services within coverage areas defined by the operational capabilities of the network structures. More than one wireless local area network might be installed to encompass a common geographical area. And, for instance in areas of heavy usage, more than two wireless local area networks might be installed to encompass a common geographical area, and in which each of the wireless local area networks is available by way of which to communicate. Depending upon operator agreements, or other criteria, a mobile terminal positioned at a location within the coverage area of the wireless local area networks has a choice of with which of the networks to communicate. Selection of with which of the networks to communicate is dependent upon any of various and sometimes selectable criteria.
Network stations, referred to as access points, of an 802.11-compatible wireless local area network generate beacons signals that include values of the network with which the access point broadcasting the beacon signal is associated. The identifier is referred to as a service set identifier (SSID). Access points, however, are sometimes configured to support multiple service set identifiers. However, only a single SSID, referred to as a primary SSID, is conventionally identified in the beacon signal. That is to say, WLAN networks typically broadcast only a single network SSID but many operators permit setting of the broadcasting to off or to configure a single access point to support multiple SSIDs. And, the access point appears as multiple wireless local area network access points. The SSIDs other than the primary SSID value are referred to as secondary SSIDs. Secondary SSIDs are revealed to a mobile terminal generally only responsive to a probe request sent by the mobile terminal that requests the identification of the secondary SSID or SSIDs.
Existing procedures by which to obtain the secondary SSIDs, however, is sometimes problematical. For instance, when a user of the mobile terminal wants to be aware of all of the WLAN networks that are available with which to communicate when the mobile terminal is positioned at a specific location and the WLAN mobile terminal has multiple WLAN access profiles, an overly time-consumptive process is required of the mobile terminal to make such identification. Conventionally, explicit probe request to all access-profile specified networks on all channels is required to obtain the information. For instance, if the number of channels upon which beacons are broadcast is 12, and a scan time per channel is 75 ms and the mobile terminal includes 10 access profiles, the product of 12×75×10=9 seconds is the time period required by which to obtain all of the information of the available WLAN networks.
A mechanism by which better to identify the available WLANs in a less time-consumptive manner is therefore required.
It is in light of this background information related to communications in a multiple-network radio communication system the significant improvements of the present invention have evolved.